The herein proposed invention is useful for driving nails and staples into wooden structures at integrated house-building factories of the forestry and wood-working industries as well as for manufacturing of wooden panels for containers and packing cases.
In tools of this kind, the housings are conventionally made of aluminium alloys. High labour consumtpion of the casting process and the inadequate strength of the bottom portion of the housing (where it is coupled with the barrel holder) affect much adversely the mass characteristics of these members, since attempts to improve the strength of the load-bearing walls involve greater metal consumption whereby the overall weight of the tool itself is also increased. A trend to reduce the mass of the hand-held tools has led to the replacement of aluminium alloys by plastics.
Not to affect the strength of the bottom portion of the housing, which is the most heavily loaded portion thereof, an optimum solution would be to relieve this portion of the housing from the peak impact forces. As, during impact loading, the action of the peak impact forces is only momentary, the strength of the housing can be substantially improved by extending the time during which an impact load is actually relayed from the barrel to the housing.
Known in the present state of the art is a hand-held fastening element driving tool (cf., laid-open Application No. 2,757,698, Federal Republic of Germany , Int. Cl..sup.3 B25C 1/100) comprising a housing which accommodates an actuator, a barrel incorporating striker, a starting device and a fastening element magazine coupled with the housing.
This tool is highly efficient and provides lasting performance.
However, the residual impulse loads developed in driving the fastening elements, are relayed, via a dash-pot, to the lower portion of the housing. Because of this, the housing needs reinforcement so as to provide the requisite strength, which renders it highly labour-consuming in manufacture.
Another hand-held fastening element driving tool (cf., German Pat. No. 1,170,338, Int. Cl. 87a, 18) is known presently to comprise a housing which accommodates an air-operated actuator. A barrel holder is locked in place with the lower portion of the body. The barrel holder incorporates a barrel with a striker. A fastening element magazine is connected to the barrel holder.
This tool is also highly efficient but demands much labour to produce its housing.
Besides, unless the fastening elements are joined in a stack, an element due to be fed in the barrel is likely to get stuck up. In such cases, additional shaking up is oftentimes necessary to push the element right home.